Many Electronic circuit projects in simple ways of learning

Top Power supply circuit diagram

You are looking at many power supply circuit diagram.  The various electronic projects need to use them as an energy source.  There are a lot of circuits categories: power supply. But sometimes you want to save time and get some ideas.  So,  I recommended the circuits with PCB lists below. Also, they are easy to build and Cheap.

Top 100 power supply circuits


3 power source for electronic devices

First, let’s meet at the three most types of Power Supply

1. Battery

A lot of circuits use a few power. So it can be powered by batteries.

This is small and easy to use anywhere. But normally they are lows voltage.


They are the best for low current using.

You should use rechargeable batteries, to reuse many times to save money a lot.

I like my children to use them. Because it is safe for him.


2. Solar

We can use it as solar power our circuit directly.


We like to use it is a solar charger for a rechargeable battery.

For example…

My son like to make solar light.


3. AC Line

We use AC line, its basic is AC Adapter, like a power supply. They are the compact units and easy to use than a battery.

We can apply them to various output voltage and currents.

When we are in a house. we should use them instead of batteries and solar, it will save our money.


We must use it carefully.  Safety first!  It is many useful but also can kill you!


Why should use a linear power supply

There are many kinds of power supply circuits. But they can all be put into two groups.

  • Linear Power supply
  • Switching mode power supply

How does liner work?

First, the AC voltage to a power transformer to raise or lower the voltage.

Then, Converted to DC voltage.

And next, applied to regulator circuit system.

It keeps the voltage and current for a load.


How Switch-mode power supply works

No transformer—It converts the AC power directly into a DC voltage without a transformer.


High frequency—this DC voltage is converted into a high-frequency AC signal.

Then, the regulator circuit inside to produce the desired voltage and current.

Linear VS Switching DC Power Supplies

In the table below is comparing various parameters of linear and switching form.

Linear VS Switching DC Power Supplies

CR: by Tekpower amazon

I love the linear power supply.


They are…

  • easy circuit diagram
  • quiet
  • high stable, durable and heavy-duty
  • low noise, ripple, delay, and EMI

Which the switching type is just the opposite.


10 Top power supply circuits

On our site have a lot of the power supply circuit. We cannot show you all. Thus, for saving you time see lists below.

1. First Variable DC Power Supply, LM317

Circuit Diagram of My First Variable DC Power Supply 1.25V to 30V at 1A using LM317

You can adjust an output voltage of 1.25V to 30V at 1.5A.  I like it.  Because… It is easy and cheap.

For example,  You can use it instead of a 1.5V battery. Continue Reading »


2. Simple Fixed DC regulator

You often look at this circuit in many appliances. They are a quite old circuit, but so useful.

Because…  It is very simple with just one transistor, Zener diode, and resistor.

The output voltage depends on the Zener Diode.

For example…

You want 12V supply, you use a 12V Zener diode.

You can make. I believe you! Continue Reading » 


3. 78xx voltage regulator—cool!

Fixed Regulator 5V,6V,9V,10V,12V 1A By IC 7805,7806,7809,7812
They are a popular 1A fixed DC Regulator, easy and cheap.

For example…

If you need  5V 1A supply for a digital circuit. We usually use LM7805 here.  Continue Reading »


4. LM350 Adjustable regulators

I sometimes need to use 3A variable voltage source.


LM317 cannot help me, easily.

In a short time, we use LM350T.

It is the best linear [email protected] Continue Reading »


5.  0-30V, 3A Adjustable DC Supply

The 0-30v variable power supply circuit diagram

We seldom use 3A Current that can adjust 0V to 30V output.

This is a better choice.

It uses LM723 as the famous regulator IC.

And here is modern design circuit, full protection than LM350T.  Continue Reading »


6. Variable power supply, 0-50V @3A

0-50V 3A Variable Power Supply Project

If you need to use voltage output over than 30V or adjust 0V to 50V.

You can use it. They have the key components, LM723, and the higher voltage 2SC5200 transistor.

Also, full overload protection.  Continue Reading »


7. Build 12V 2A power supply by a hammer

Hammer a nail into the parts joint

If you hurry up and no PCB. This idea may good. You can build a 12V 2A adapter easily and cheap. With using hammer and snail on wood board.   Also, to learn more.  Continue Reading » 


8. 15V Daul power supply 1A

15V dual power supply circuit projects

If you need to use many circuits using OP-AMP. For example, Preamplifier with tone control and more. They need to use +/- 15V power supply. We have 3 circuit ideas for you.  Continue Reading >>

Working Learning

Learn 7805 circuit pinout and more
See LM317 pinout and how to use

Fixed Volts regulator: 3V, 6V, 9V, 12V

5V power suppliesDigital power supplies

9 volts

Low volts

Low Drop Out Voltage

Simple and Ideas

Adjustable Power Supply Circuit

Under 1A

2A Output Current

3A Output current

High Current (5A up)

High voltage (100V up)

Dual rail regulator & Multiple Voltage


Constant Current Source

Tiny Circuit Learning

Simple constant voltage circuit using small transistors +New


Switching Mode Power Supply circuits

These are DC switching power supplies. To be ideas on building the projects or tools. Because they have a small size and cheaper than the linear power supply.


My site begins to have many circuits. Until friends said that difficult to see circuits or projects as he wants.

Particular DC switching power supply has very useful. The list below are ideas to build the great power supply that small and saving money. For application or learning.

So, I collect these circuits for ease of accessing the projects that I interested in. Also, they may be useful for you, too.

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This Post Has 3 Comments

  1. Thanks a lot for the information

  2. I am lost, I need 1.5 volt battery P.S to light two 1.5 v miniature lights for my Buddy L trucks.The lights I have are 1.5 v, .3 amp. these could be wrong. Is there a better choice. HELP ?

  3. PS, USB 5vto 1.5v step down converter circuit, I think this one will work, I require 1.5 v battery source PS to light two 1.5 v miniature lights for my Buddy L. Do I purchase everything from you how does it work ?

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